The shooting of UnitedHealthcare CEO Brian Thompson in December 2024, where a 3D-printed gun was used, highlights the escalating threat of these untraceable “ghost guns.”
These firearms, made partially or entirely with commercially available 3D printers, are increasingly appearing in criminal activity, posing significant challenges for law enforcement and policymakers worldwide. The U.S. Supreme Court is currently reviewing the legality of federal restrictions on these weapons.
The first documented criminal case involving a 3D-printed gun occurred in the UK in 2013. Since then, their prevalence has grown rapidly. Between 2017 and 2021, U.S. law enforcement seized nearly 38,000 suspected ghost guns, according to a 2024 US Bureau of Alcohol, Tobacco, Firearms and Explosives report.
In 2021 alone, over 19,000 were traced, a sharp rise from just over 8,500 in 2020. New York state saw a dramatic increase from 100 seizures in 2019 to 637 in 2022. Arrests are also on the rise, with 108 globally in the first half of 2023, compared to 66 in all of 2022.
North America leads in 3D-printed gun-related arrests (166 from 2013 to June 2023), followed by Europe (48) and Oceania (24). The U.S. accounts for 36% of global arrests in 2023, closely followed by Canada (34%). The UK and Australia represent 10% and 8% respectively.
According to a report in The Conversation, these weapons have been linked to a wide range of groups, including far-right extremists, ethno-separatists, jihadists, left-wing anarchists, organised crime, and pro-democracy rebels. From 2019 to mid-2022, at least nine cases in Europe and Australia involved extremists, terrorists, or paramilitary groups attempting or succeeding in producing 3D-printed firearms. Analysis of 165 cases from 2013 to mid-2024 shows that 15% were terrorism-related, with far-right groups being the most frequent users.
The lack of serial numbers on these homemade weapons makes them difficult to trace, a key attraction for criminals. Global regulatory approaches vary significantly.
Japan strictly prohibits unauthorised firearm production, including 3D-printed guns, with severe penalties. Canada effectively banned ghost guns in 2023, requiring licenses for possession or manufacture. Australia criminalises both making and, in some states, possessing blueprints for 3D-printed firearms, with potential prison sentences of up to 21 years. The EU broadly prohibits making or owning homemade firearms, with varying laws and penalties, including criminalising possession of digital files. The UK recently updated its laws to specifically ban possessing, buying, or producing parts for 3D-printed guns, and is considering banning blueprint possession.
In the U.S., the Second Amendment and First Amendment pose unique regulatory challenges. While selling 3D-printed firearms requires a federal license, producing or owning them for personal use is permitted, including 3D-printing the lower receiver. Current federal law, under Supreme Court review, requires 3D-printed gun kits to meet specific guidelines, including licensing, background checks, and serial numbers. Converting semi-automatic firearms into automatic weapons using 3D-printed “Glock switches” is illegal and carries significant penalties.
State-level regulations are also emerging. By November 2024, 15 U.S. states had implemented regulations on ghost guns, typically requiring serial numbers, background checks, and reporting of 3D-printed firearm production. For example, New Jersey mandates serial numbers and registration, while New York is considering making 3D-printed firearm manufacturing a felony.
As 3D printing technology advances, the challenge of regulating these weapons and mitigating the threat they pose to public safety will likely intensify.
